Measurement of the nuclear modification factor for high-$p_\mathrm{T}$ charged hadrons in p+Pb collisions with the ATLAS detector

The charged hadron spectra in p+Pb and pp collisions at $\sqrt{s}=5.02$TeV are measured with the ATLAS experiment at the LHC. The measurements are performed with p+Pb data recorded in 2013 with an integrated luminosity of 25nb${}^{-1}$ and pp data recorded in 2015 with an integrated luminosity of 28pb${}^{-1}$. The p+Pb results are directly compared to pp spectra, as a ratio scaled by the number of binary nucleon-nucleon collisions, the nuclear modification factor $R_\mathrm{pPb}$. The study of $R_\mathrm{pPb}$ allows a detailed comparison of the collision systems in different centrality intervals and up to high transverse momentum. It is shown that the nuclear modification factor does not have any significant deviation from unity in the high transverse momentum region.